well... this isn't the best answer, but...

go to any stage, sometimes on top of the loops, you can find the following:

-green pretective cover (if that what you call it)
prevents losing coins until secend hit.

*-blue pretective cover
does the same thing as green but draws close coins to you

-5 rings
give you, well... 5 rings

-10 rings
give you 10 rings

-? rings
gives you 1 to 30 rings (or something like that)

you are looking for #2. (the one with the *)

Boxes that say ? can give you from 1 to 99 rings

i just go on green hill zone alot